Well tool for determining the torque applied to well pipe sections



Dec. 15, 1959 Filed Sept. 15. 1954 P. E. DAVIS, JR WELL TOOL FORDETERMINING THE TORQUE APPLIED TO WELL PIPE SECTIONS 3 Sheets-Sheet lPHlLlP E. DAVIS JR.

INVENTOR.

ATTORNEY BWMW Dec. 15, 1959 P. E. DAVIS, JR 2,916,954

WELL TOOL FOR DETERMINING THE TORQUE APPLIED TO WELL PIPE SECTIONS FiledSept. 15, 1954 s Sheets-Sheet 2 PHILIP E.

ATTORNEY Dem 1 P. E. DAVIS, JR

WELL TOOL FOR DETERMINING THE TORQUE APPLIED TO WELL PIPE SECTIONS 3Sheets-Sheet 3 Filed Sept. 15, 1954 QQQ NK P/7/// o f. Dav/a, INVENTOR.

W v/M United States Patent WELL TOOL FOR DETERMINING THE TORQUE APPLIEDTO WELL PIPE SECTIONS Philip E. Davis, In, Houston, Tex.

Application September 15, 1954, Serial No. 456,152

Claims. (Cl. ill-52.4)

The present invention relates to a device for limiting the torque orforce applied to a member.

In the drilling of wells by the rotary method, the well hole is cut inthe earth by a drill bit which is suspended on a string of pipe, and asthe hole is deepened, it is necessary to add sections of pipe to thepipe string.

In order to screw a pipe section into place in the drill string, thepipe section is picked up oif the pipe track, raised into position inthe derrick and then lowered vertically in the drilling rig until itsend contacts the end of the drill string suspended in the well boreabove the drilling platform. A cable, chain or rope is wrapped aroundthe pipe section adjacent the lower end thereof. Pipe tongs are securedto the pipe to which another portion of the same rope, cable or chain isattached.

The other end of the chain or cable is wrapped around a rotatable powershaft, so that when such shaft is rotated the cable is tightened andcontinues to wrap around the power shaft. The end of the cable wrappedaround the pipe section unwinds and as it unwinds it rotates the pipesection and causes it to threadedly engage with the drill string. Afterthe one portion of cable, chain or rope is unwound, the pipe sectionsare tightened by exerting a pull on the portion of the cable connectedto the pipe tongs.

It is extremely time consuming to manually clutch the power shaft and itis even more difiicult to regulate the torque applied to the pipesection as it is screwed to the drill string.

Power operated clutches have been attempted to relieve some of theproblems of manual clutching of the power shaft; however, such powerclutches often cause the pipe section to screw too hard to the drillstring so that it binds and is difiicult to unscrew. Also, such deviceshave caused thread failure in the pipe sections by placing too muchstress and strain thereon.

Also, since it is not uncommon to remove the drill string from the wellbore, section by section, to replace a bit, or for other reasons, agreat deal of time and money may be lost in tryin to unscrew pipesections which have been screwed too tightly so that they are stucktogether.

Additionally, whether the power shaft is manually or automaticallyclutched to operatively engage it with the cable, commonly referred toas a jerk line, it is not uncommon to not exert enough force on thecable so as to securely screw the pipe section to the drill string. Insuch event the drill string may separate in the well here duringdrilling operations thereby causing further delay and expense.

The present invention overcomes the above difiiculties in that itprovides a mechanism whereby pipe sections are screwed a predeterminedamount, or to a predetermined respectively.

Still a further object of the invention is to provide a device forautomatically disengaging a power mechanism from members being rotatablyengaged when a predetermined amount of force has been applied to suchmembers.

Still a further object of the invention is to provide in a clutchmechanism for operatively engaging a source of power relative to pipesections whereby they may be screwed together, means for automaticallyreleasing the clutch when the pipe sections have been screwed apredetermined amount.

Yet a further object of the invention is to provide a mechanism whichautomatically releases a clutch from a power source when the reaction ofthe power source has reached a predetermined amount.

Yet a further object of the invention is to provide a mechanism forautomatically releasing a clutch mechanism from a power shaft when thereaction of the power supplied reaches a predetermined point.

Yet a further object of the invention is to provide a mechanism forautomatically releasing a clutch mechanism from a power shaft when thereaction of the power supplied reaches a predetermined point, said meansincluding a means whereby it may be adjusted for releasing the clutch atany predetermined or desired point.

A further object of the invention is to provide means for disengaging apower mechanism from members being rotatably engaged when a desiredamount of force has been applied to such members, said means beingadjustable for disengaging at any desired amount of force.

Other objects and advantages of the invention will become more readilyapparent from a consideration of the following description and drawingswherein:

Fig. 1 is a vertical sectional view illustrating an embodiment of theinvention;

Fig. 2 is a sectional view, partly in elevation, on the line 2-2 of Fig.1 showing the means for actuating the clutch;

Fig. 3 is an enlarged view of that form of the invention shown in Fig.1;

Fig. 4 is a schematic illustration showing the present inventionoperatively connected to a line; and

Fig. 5 is an isometric view, partly in section, of the presentinvention.

The present invention, for purposes of illustration only, is describedin detail in relation to making up pipe sections; however, it should beunderstood that it can be easily adapted for operation with draw worksor other power mechanism without departing from the scope of theinvention. Generally speaking, it may be used in any situation forcontrolling the application of energy between a drive and a drivenmember.

In Fig. 3 an elongated shaft 4 is illustrated which is provided at oneend with the flange 5 whereby it is adapted to be secured to a suitableextension or power take-off of any suitable power mechanism such as, forexample, the draw works or other power mechanism. Such shaft has securedat its opposite end a cathead 6 which may be suitably engaged with theshaft 4 by any means such as the bolts 7 extending through the end 8 ofthe cathead and engaging in the end 9 of the shaft.

A spool 10 is supported by a sleeve bearing 11 on the shaft 4 whichspool has secured thereto the gear ring 12, such gear rnig being securedto the spool by any suitable means such as the bolts 13 as illustratedin the drawings. For the purpose of illustration and description thegear 12 and spool 10 may be termed the driven members.

A drive gear 14 is secured to the elongated shaft 4 and adapted torotate therewith. As shown in the drawings, such gear maybe secured onthe shaft 4 by means of the key 15 which fits in keyways 16 in the gearand shaft A clutch drum 17 is supported by sleeve bearing 18 on theshaft 4 and such drum is provided with pinions 19 which are freelyrotatable relative to such drum but are mounted thereon by means of thebolts 2% which extend through the pinions and into the drum 17 asillustrated at 21in Fig. 3. As shown in the drawings, the pinions 19engage with the drive gear 14 andgear ring 12, and form a drivingconnection means between the drive gear 14' and the driven members and12.

A-clutch element is illustrated at 22 and is mounted whereby it may beengaged against the clutch drum 17, such clutch element being supportedby the annular lateral projection 23 which is secured to the clutchelement carrier 24. The clutch element carrier 24 is in turn supportedat its inner periphery by the bearing 25 which rests on the hub 26 ofthe clutch drum.

The clutch element 22 is of a suitable inflatable type and is providedwith an opening 27 with which the passage means 28 communicates wherebysuch element may be inflated to expand against the annular clutchsurface 29 of the clutch drum 17. Any suitable inflatable clutch elementof various well known types'may be used and it is not believed necessaryto give a detailed description of any of such elements, since theconstruction thereof is not critical in relation to the presentinvention; however, one such clutch element commonly used is of thepneumatic type and such type may be employed in the present invention.

Connected to the clutch element carrier 24 is the yoke 31, such yokehaving openings 32 through the prongs thereof whereby a bolt 33 may beengaged therethrough and through the opening 34 in the clutch elementcarrier 24 to position the yoke on the clutch element carrier. A

nut 35 maybe engaged with the bolt to retain it'in engaged position wtihthe yoke 31 and clutch element carrier 24; The yoke extends from theclutch element carrier and is secured at its end 36 to the plunger rod37 which plunger rod extends into the hydraulic cylinder 38. The plungerrod 37 has secured thereto .on the end projecting in the hydrauliccylinder 38 a piston element adapted to force liquid through the conduit39 in response to movement of such piston element and connected pistonor plunger rod 37.

This portion of the invention is more clearlyillustrated in Fig. 2 ofthe drawings wherein the conduit 39'is communicated with the gage 40 andis also communicated with the hydraulically'operated air valve 41 andregulator 42. The air valve 41 is operated by the pressure of the fluidin the conduit 39 and when actuated it releases the air from the clutchelement 22 so as to disengage the clutch element and thereby disengagethe drive gear 14 relative to'the driven gear 12.

When the apparatus'is in the position shown in Fig. l 3 of the drawings,the pneumatic clutch element 22 is deflated and disengaged relative tothe clutch surface 29 of the clutch drum 17. When the shaft 4 is rotatedby suitable means such as the draw works as previously de scribed, theclutch element carrier 24 remains stationary andthe clutch drum 17rotates slowly about the elongated shaft 4 as the pinions 19 walk aroundthe gear ring 12.

Since, as above mentioned the clutch element 22 is deflated anddisengaged relative to the clutch surface 29' of the clutch drum 17there is no driving connection between the drive gear 14 and the spool10, and no power can be supplied from the rotating power shaft 4 so asto rotate the spool 10.

In order to engage the drive gear or member. 14 on rotating power shaft4 with the driven gear or member12 the pneumatic clutch is inflatedwhereupon. it engages.

against the clutch drum 17 which forms a drivingconnection between thedrive gear 14 and the driven gear ringlZ by means of the pinions 19.This effects rotation I relationship established between the gearconnection will be continued until the clutch element 22 has beendeflated so that it will release relative to the clutch drum 17. When awork load is placed on the spool 10, the reaction to such load throughthe pinions to the clutch drum 17 and clutch element carrier 24 causesthe clutch element carrier 24 to tend to move or rotate. When movementof the clutch element carrier 24 occurs the fork 31 connected to pistonrod 37 is moved whichjalso moves the piston in the;

engages such element from the surface 29 of clutch drum 17. Thisdisconnects the drive and driven relationship in the mechanism so thatno additional power is supplied from the shaft 4 through the drivingconnectionjto the spool 10.

The regulator 42 may be placed in the line and set so that the valve 41will trip at a pre-set or desired pressure. In this manner the pressureat which the valve 41 may be tripped can be varied or adjusted byadjustment of the regulator, so that if in some situations it is moredesirable to have a release of the clutch effected at a differentpressure or condition, then the regulator 42 may be adjusted so that itwill in turn trip the valve 41 when the pressure in conduit 39 haseither built up to a greater orlesser degree according to its setting.

While it is believed that the operation of the invention is apparent byreason of theforegoing description, it will be assumed that theapparatus is to be applied for use in screwing together pipe sectionssuch as commonly encountered in the drilling of an oil or gas well.

In order to screw adjacent pipe sections together, one end portion 55 ofthe cable or rope 60 is adapted to be wrapped around one of the pipesections 56, as illustrated in Fig. 4. Another end portion 57 of thecable or rope is secured to the tongs 58 which tongs are also engageddrum 17 and thereby operatively connect the spool 10 v to the shaft 4through the gear connections 14, 12 and 19. As the spool 10 is therebyrotated, force or energy is applied or transmitted to the cable 60connected therewith so as to rotate the pipe section 56 and connect itwith the next pipe section. As the pipe sections are screwed together,the rope end 55 unwinds and disengages from the rotatable pipe section56. Force is then transmitted to rotate thepipe section through rope end57 and tongs 58. As the pipe sections are thus screwed together tighter,a greater loadbuilds upon the spool 10 and as this occurs the reactiveforce occurring through the gear 12 7 Since clutch drum 17 and clutchelement carrier 24 are in effect connected together by the expandedelement 22, such reactive force is in turn transmitted to the clutchelement carrier 24 to cause incremental rotational moveand pinions 19 tothe clutch drum 17 increases.

ment thereof. As the clutch element carrier 24 moves,

the yoke 31 and piston rod 37 are also moved which in turn moves thepiston in the hydraulic cylinder 38 to buildup a pressure in the line39. Whenv the pressure in line 39 has built up to a point to trip thehydraulically operated air valve 41, the pressure in line 28 will bedissipated thereby effecting deflation of the clutch elemeat 22 whichdisconnects the drive portion of the assembly, namely, power shaft 4 anddrive gear 14 relative to the driven portion of the mechanism, namely,gear ring 12 and spool 10. This in turn releases the energy exerted bythe spool on the cable and the pipe sections being screwed together toprevent such pipe sections being screwed together too hard or having toomuch force applied thereto beyond that predetermined force set by theregulator 4-2.

As additional sections of pipe are added -to the drill string, theapparatus will screw the sections of pipe together up to a predeterminedamount of force and will thereupon release to prevent any additionalforce being applied thereto to prevent galling or undue sticking orbinding of the members together.

Also, the mechanism permits sections of a drill pipe to be connectedtogether and screwed together to a uniform predetermined amount offorce.

Heretofore serious difliculty has been encountered in attempting to makeup drill string wherein a power operated clutch such as that describedherein is used in that no satisfactory mechanism has been provided forreleasing the clutch after the pipe sections have been screwed togethera certain amount. The automatic clutches or other power operatedmechanisms heretofore used in making up the pipe sections have causedgalling and binding of the pipe sections because they would not releaseafter the pipe sections had been made up to a suitable point, but wouldcontinue to apply a torque or force to the pipe sections until the ropeof cable had been'manually released either from the pipe section or thespool. Of course, since the mechanism continues to apply a force to thepipe section by means of the cable, release of the rope is impossiblesince it is wound around the spool and is also wound tightly around thepipe section, However, the present invention overcomes this diflicultyin that it provides a mechanism which permits the automatic clutch to beused in making up the pipe and then releases or disengages the drivingmechanism relative to the driven mechanism after the pipe section hashad a predetermined force applied thereto. This serves to limit theforce applied and prevents over application of force and binding of thepipe sections together. Suitable oil seals as illustrated at 52 may beprovided in the apparatus.

Furthermore, the device may be used to also measure the amount of torqueexerted in a mechanism by the pressure gage 40 which reading may bedesirable under certain circumstances.

The invention has been described in detail as being particularly usefulin screwing sections of pipe together to form a drill string, however,such is to serve merely as an illustration of the invention and is in noway intended as a limitation upon the uses for the invention.

The construction of the regulator 42, as well as valve 41 is of anysuitable well known type and it is therefore not deemed necessary togive a detailed description thereof.

In some situations, it may be desirable-to trip valve 41 by means of afluid such as air, steam or the like.

Broadly, the invention relates to an apparatus for limiting the energyor power supplied from a drive to a driven member and more particularlyto an apparatus which automatically releases the drive member relativeto the driven member when a predetermined force has been applied to suchdriven member.

What is claimed is:

1. Apparatus for releasing a drive member relative to a driven memberwhen a predetermined force is exerted between the drive and drivenmembers comprising, a power shaft for supplying power to the drivemember inflatable clutch means operative associated with said powershaft whereby said shaft may be engaged for transmitting power betweenthe drive and driven members, and additional means associated with saidclutch and operable to disengage said shaft relative to the drivenmemher when a predetermined force is exerted between the drive anddriven members, said last named means including valve means forreleasing said inflatable clutch means when a predetermined force iseverted between the drive and driven members. I

2. Apparatus for releasing a drive member relative to a driven memberwhen a predetermined force is exerted between the drive and drivenmembers comprising, a power shaft for supplying power to the drivemember, inflatable clutch means operatively associated with said powershaft whereby said shaft may be engaged to transmit power between thedrive and driven members, additional means associated with said clutchand operable to disengage said shaft relative to the driven member whena predetermined force is exerted between the drive and driven members,said last named means including valve means for releasing saidinflatable clutch means when a predetermined force is exerted betweenthe drive and driven members, and additional means for regulating saidvalve means to control the force exerted between the drive and. drivenmembers necessary to effect release of the drive relative to the drivenmember.

3. The combination recited in claim 1 wherein said additional means alsoincludes means to instrumentally measure the force exerted between thedrive and driven members when said inflatable clutch releases todisengage said power shaft relative to said driven member.

4. In a torque transmitting apparatus, a drive member, said drive memberincluding a power shaft, gear means mounted thereon to rotate therewith,a driven member rotatably supported on said power shaft for relativerotation therebetween, a gear ring mounted on said driven member torotate therewith and in spaced, aligned relation to said gear means onsaid power shaft, a clutch drum rotatably supported on said power shaftfor relative rotation therebetween, and pinions rotatably supported onsaid drum and engaged with each said power shaft gear means and saiddriven member gear ring whereby torque may be transmitted from saiddrive to driven member when relative movement between said clutch drumand power shaft is arrested.

5. The combination recited in claim 4 including means to arrest relativemovement between said clutch drum and power shaft.

6. The combination recited in claim 5 wherein said arresting meansincludes an inflatable clutch adjacent said drum and adapted to beinflated to engage said drum to arrest relative movement between saiddrum and power shaft.

7. The combination recited in claim 5 wherein said arresting meansincludes an inflatable clutch, a clutch element to support saidinflatable clutch adjacent said drum, a clutch element carrier rotatablysupported on said clutch drum, but locked for rotation therewith whensaid inflatable clutch is inflated against said drum, said drum andclutch element carrier rotatable in response to reaction force exertedbetween said drive and driven members, a piston means secured to saidelement carrier and movable upon rotation of said carrier in response toreaction force, a cylinder in which said piston is mounted, a fluidconducting conduit communicating with said cylinder whereby movement ofsaid piston by rotation of said carrier in response to reaction forcecreates a pressure in said cylinder and said fluid conducting conduit,hydraulically operated air valve means mounted in said conduit andcommunicating with said inflatable clutch whereby said valve meansreleases said inflatable clutch from engagement with said drum inresponse to the pressure created in said fluid conduit in response tothe reaction force created, regulating means mounted in said conduit toregulate the fluidl pressure in said conduit at which said valve meansactuates to release said inflatable clutch, and means to instrumentallynote the reaction force exerted between said drive and driven means whenrelease is effected.

8. Ina torque transmitting apparatus, a drive member, said drive memberincluding a power shaft, gear means mounted thereon to rotate therewith,a driven member rotatably supported on said power shaft for relativerotation therebetweema gear ring mounted on said driven member to rotatetherewith and in spaced, aligned relation to said gear means on saidpower shaft, a clutch drum rotatably supported on said power shaft forrelative rotation therebetween, pinions rotatably supported onsaid drumand engaged with each said power shaftgcar means and said driven membergear ring whereby torque may be transmitted from said drive todrivenmember when relative movement between said clutch drum and powershaft is arrested, means to arrest relative movement between said clutchdrum and power shaft,,said arresting means including an inflatableclutch adjacent said drum and adapted to be inflated to engage said drumto arrest relative movement between said drum and power shaft, andadditional means associated with said inflatable clutch and operable todisengage said drive member relative to said driven member when apredetermined reaction force is exerted between said drive and drivenmembers, said last named means including valve means for releasing saidinflatable clutch means when a predetermined reaction force is exertedbetween said drive and driven members.

9. The combination recited in claim 8 wherein said additional means alsoincludes means to instrumentally measure the reaction force exertedbetween the drive 0 U and driven members when said inflatable clutchreleases.

10. The combination recited in claim 8 including addi tional means forregulatingsaid valve means to control" the reaction force exertednecessary to effect release of saididrive relative to said drivenmember.

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